Automated die-gap changes

Film extruders can reduce downtime needed for die-gap changes with a new single-point adjustment mechanism that automatically changes sheet or film thickness and eliminates the need for flexible-lip bolts or alternate lower lips. The previous FastGap still required some reassembly time and lubrication, but the newly patented Toggle FastGap removes downtime during those steps as well.

By applying force at regular intervals, the die gap is altered along the die's lower lip, which bends it. The system is actuated by a special wrench, which an operator uses to turn an adjusting nut at one end of the die. The need for lubrication is eliminated, since instead of a stationary bar with an array of male and female keys hitting one another, the new system has an array of toggles along the width of the die. Now instead of sliding, there is a rotary motion of the pins and bushings at the ends of the toggle shafts.

Since adjustments of the flexible upper lip affect the die opening, the system triples the range of available gap settings, allowing the die opening to be varied in .2-inch (5.1-mm) increments, just by moving the lower lip. If the upper lip is altered, an additional .1 inch (2.5 mm) is available. Extrusion Die Industries LLC, Chippewa Falls, WI; 715-726-1201; www.extrusiondies.com